Nub.
Mine has 3 speed nocks on each end of the string.

I usually dont go to the trouble of seperating the string to install cats whiskers but being between the 2 colors should not have any adverse effect just makes it hard to slide them.
Just backing out the screw 1/2 a turn should not make that big a change in the nocking point.

On a friends Pat Last week when I was shooting with him every time he drew the bow there was a clicking sound.
Took me 10 minutes to figure out where it was coming from the grub screw on the cable guard rod had come loose I just tightened it back down and the clicking went away.
Check to make sure that the grub screw is snug.
You know the one that is under the other one